21377673 has 12 divisors (see below), whose sum is σ = 30941040. Its totient is φ = 14223096.

The previous prime is 21377663. The next prime is 21377677. The reversal of 21377673 is 37677312.

It is not a de Polignac number, because 21377673 - 2⁸ = 21377417 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21377677) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2958 + ... + 7176.

It is an arithmetic number, because the mean of its divisors is an integer number (2578420).

Almost surely, 2^21377673 is an apocalyptic number.

It is an amenable number.

21377673 is a deficient number, since it is larger than the sum of its proper divisors (9563367).

21377673 is a wasteful number, since it uses less digits than its factorization.

21377673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4788 (or 4785 counting only the distinct ones).

The product of its digits is 37044, while the sum is 36.

The square root of 21377673 is about 4623.5995717622. The cubic root of 21377673 is about 277.5365230720.

The spelling of 21377673 in words is "twenty-one million, three hundred seventy-seven thousand, six hundred seventy-three".